In the field of recording or imaging systems, the laser or optical maser has been used to provide high speed and high intensity operation. The laser amplifies light and radiates the amplified light in the form of a coherent, extremely high intensity light beam. The light beam may be modulated or controlled in a manner wherein an image is recorded on a film or like record media in a scanned light pattern of a succession of lines. It is generally desired to improve the laser scanning or imaging technique in these systems.
Representative documentation in the field of recording or imaging systems includes U.S. Pat. No. 3,154,371, issued to W. R. Johnson on Oct. 27, 1964, which discloses an optical recording system utilizing a laser light source, a rotating reflector, a curved platen to correct for geometric distortions of the scanning beam and vacuum pressure exerted at the surface of the platen to hold the film strip secure in a desired plane.
U.S. Pat. No. 3,809,806, issued to R. Walker et al. on May 7, 1974, discloses film recording apparatus having a laser, a beam expander, a lens, a rotating reflector and a curved bridge member for supporting the film.
U.S. Pat. No. 3,874,621, issued to L. R. Blair et al. on Apr. 1, 1975, discloses a recording system using a gas laser along with a curved air film platen with small air jets providing an air bearing.
U.S. Pat. No. 3,938,191, issued to H. I. Jarmy on Feb. 10, 1976, discloses a read head carriage which is supported on air bearings and is driven by a precision lead screw.
U.S. Pat. No. 3,953,859, issued to J. W. Locke on Apr. 27, 1976, discloses apparatus for recording images on film by using a laser beam, a film transport clamped to a carriage and having an arcuate-surface platen with a vacuum box to provide suction for holding the film.
U.S. Pat. No. 4,168,506, issued to S. I. Corsover on Sept. 18, 1979, discloses a curved film guide to position the film during both recording as well as reading mode and having curved, porous surfaces through which air is passed to support the film.
U.S. Pat. No. 4,271,415, issued to M. Murakoshi et al. on June 2, 1981, discloses a laser COM device having a platen which is adapted to clamp the film between first and second pairs of rollers.
U.S. Pat. No. 4,293,864, issued to R. D. Scott on Oct. 6, 1981, discloses a laser scanner transport having a translation motor to move a modulated laser beam back and forth inside a transparent cylinder, and a spinner motor to cause rotation of the beam to describe a helical pattern on the cylinder and the printing medium thereon.
And, U.S. Pat. No. 4,358,774, issued to R. L. Wilkinson on Nov. 9, 1982, discloses a recording system which utilizes a write laser and a read laser and control means for maintaining proper focus of the laser beam.